<?php

 class Shape
{
    public function getArea(){ }


}


class Rectangle extends  Shape
{
    private $instance;
    private $width,$height;
    public function _construct()
    {
        //$this->height=$height;
        //$this->width=$width;
    }
    public function getArea()
    {
        return $this->width*$this->height;
    }
}
class Rect extends Rectangle
{
    public function _construct($width)
    {
        parent::_construct($width,$width);
    }
}

$a=new Rectangle();
$b=new Rectangle();

?>